Apparatus for spreading fluid

ABSTRACT

A vehicle-carried fluid spreader including a fluid supply, a pair of elongated spray bars having fluid passages extending therethrough, and valve-controlled orifices on the spray bars through which fluid may be sprayed from the bars. The spray bars are connected through a swing joint which permits swinging of one relative to the other about an upright axis and about a horizontal axis extending longitudinally of the vehicle. The swing joint has a pair of fluid-flow paths extending therethrough. One of the flow paths carries fluid through the swing joint from the supply to the inlet end of the passage in one of the spray bars and the other path carries fluid from the outlet end of the passage in the one spray bar to the inlet end of the passage in other bar. This permits circulation of fluid flow through first one and then the other of the spray bars. A valve-controlled shunt conduit connects the second spray bar directly to the supply and may be opened to produce concurrent fluid supply to the first and second bars.

[ 1 Oct. 1, 1974 [57] ABSTRACT A vehicle-carried fluid spreader including a fluid supply, a pair of elongated spray bars having fluid passages extending therethrough, and valve-controlled 0rifices on the spray bars through which fluid may be sprayed from the bars. The spray bars are connected through a swing joint which permits swinging of one relative to the other about an upright axis and about a horizontal axis extending longitudinally of the vehicle. The swing joint has a pair of fluid-flow paths extending therethrough. One of the flow paths carries fluid through the swing joint from the supply to the inlet end of the passage in one of the spray bars and the other path carries fluid from the outlet end of the passage in the one spray bar to the inlet end of the passage in other bar. This permits circulation of fluid flow through first one and then the other of the spray bars. A valve-controlled shunt conduit connects the second F. Kenneth Hill, 1821 Bisbee, Klamath Falls, Oreg. 97601 Filed: May 29, 1973 Appl. No.: 364,607

US. Cl..... 239/125, 239/130, 239/168, 239/551 Int. B05b 9/00 Field of Search 239/125, 130, 132.1, 159, 239/135, 166, 167, 168, 551, 562, 124

United States Patent Hill [ APPARATUS FOR SPREADING FLUID [76] Inventor:

spray bar directly to the supply and may be opened to produce concurrent fluid supply to the first and second bars.

TIONS Great Britain..................,.,. 239/130 7/1970 239/159 16 Claims, 5 Drawing Figures FOREIGN PATENTS OR APPLICA Primary ExaminerLloyd L. King Assistant Examiner-Andres Kashnikow M Attorney, Agent, or FirmHartwell, Hartwell, Dickinson &'S

APPARATUS FOR SPREADING FLUID BACKGROUND OF THE INVENTION This invention relates to apparatus for spreading fluid. More particularly it relates to vehicle carried spreader apparatus which includes multiple spray bars, one of which is mounted for swinging movement relative to the other, and means for circulating fluid therethrough.

In the spreading of fluids, such as asphalt for roads, a tank truck often is used with spray bars extending across the back end of the truck. To provide a wide spray path, spray bars which extend laterally outwardly beyond opposite sides of the truck often are used. Since various obstructions may be encountered during operation, it is generally desirable to have those portions of the spreader bars which extend beyond opposite sides of the truck mounted for swinging, whereby they may move out of the way of obstacles, rather than being broken off as the truck progresses over the road.

When working with materials, such as asphalt, it is often necessary to provide for recirculation of the material through the spray bars and tank when not spraying. Explaining further, when hot ashalt is being applied the material generally is heated in the tank of the truck, and then is pumped to spray bars along the back end of the truck. If the asphalt cools in the spray bars it becomes less fluid and has a tendency to clog the apparatus. To prevent this the asphalt must be continuously circulated through the spray bars and then back to the tank for reheating if spraying is not occurring.

A general object of the present invention is to provide novel fluid-spreading apparatus which includes a pair of elongated spray bars having fluid flow passages extending therethrough, a fluid supply, and a swing joint mounting one of the spray bars for swinging relative to the other about a pair of axes disposed at a substantial angle relative to each other. The swing joint has a pair of fluid flow paths extending therethrough permitting fluid to circulate from the tank of the truck successively through one and then the other of the spray bars. With such apparatus, fluid may be circulated from the supply through the spray bars, while still permitting swinging of one of the spray bars. The one spray bar may swing fore and aft relative to the truck to clear obstructions, and may swing vertically to a substantially upright position adjacent the side of the truck to decrease side-to-side dimensions for travel between work areas.

Another object is the provision in such apparatus of a valve-controlled conduit, through which fluid may be supplied directly to the nonswinging spray bar concurrently with supply of fluid to the swinging bar. For circulation of fluid through the bars when not spraying the valve is closed, and for spraying the valve may be opened to supply sufficient quantities of fluid directly to the nonswinging bar.

Yet another object of the present invention is the provision of novel poppet valve-controlled orifices through which fluid may be sprayed from the bars. In an embodiment of the invention a seat surrounds an orifice on a spray bar, and a poppet valve head is shiftable between a closed position in sealing engagement with the seat and an open position spaced from the seat. Also included is a guide sleeve which surrounds the valve head and its associated stem for guiding their movement toward and away from the seat. The guide sleeve has enlarged openings therein through which fluid may circulate as it flows through the spray bar. and through which the fluid may flow to the orifice when the valve is opened.

An advantage of such a valve is that fluid may flow freely therethrough to heat and clear fluid from the valve stem and head as it circulates through the passage and also provides free fluid flow to the orifice. Further, when cold asphalt, which may be an emulsion of asphalt and water, is being worked, the provision of large openings (rather than narrow, constricted openings which have been used in the past) prevent demulsification from occurring. If demulsification occurs, as happens with previous devices, the water and asphalt separate and there is a tendency for the asphalt to harden and clog the system.

DRAWINGS;

These and other objects and advantages will become more fully apparent as the following description is read in conjunction with the drawings, wherein:

FIG. 1 is a rear end view of a tank truck with spreader apparatus according to an embodiment of the invention supported on the rear of the truck;

FIG. 2 is an enlarged perspective view of the spreader apparatus illustrated at the left side of the truck of FIG. 1, including a portion of a central spray bar, a swingable spray bar, and a swing joint interconnecting the two;

FIG. 3 is an enlarged cross-sectional view of the swing joint taken generally along the line 33 in FIG.

FIG. 4 is an enlarged perspective view of a portion of a spray bar and a poppet valve-controlled orifice therein; and

FIG. 5 is a schematic fluid flow diagram illustrating operation of the apparatus in one: condition for circulating fluid.

DETAILED DESCRIPTION OF AN EMBODIMENT OF THE INVENTION Referring now to the drawings and first more specifically to FIG. 1, at 10 is indicated generally a tank truck, or vehicle, having a tank 12 supported adjacent its rear end on wheels 14.

At 18 is indicated generally spreader apparatus constructed according to an embodiment of the invention.

The apparatus includes an elongate, hollow center 7 spray bar 20 secured in a substantially stationary position relative to the truck extending horizontally across the back end of the truck, and a pair of oppositely disposed, elongated hollow wing spray bars 24, 26 extending outwardly from opposite ends of the center bar. As seen in their operative positions, the wing spray bars extend laterally outwardly beyond opposite sides of the truck.

The wing spray bars 24, 26 are mounted on the truck through swing joints 34, 36, for swinging relative to the truck and center bar 20. The wing spray bars are mounted for swinging about substantially horizontal axes paralleling the longitudinal center line of the truck between lowered positions, shown in solid outline in FIG. 1, extending outwardly from and substantially in alignment with opposite ends of center spray bar 20, and raised positions illustrated in dot-dash outline at 24A, 26A, extending upwardly along opposite sides of the truck. Elongated, fluid-actuated rams 30, 32 are operatively connected to wing spray bars 24, 26, respectively, for swinging them between their lowered and raised positions. The wing spray bars also are mounted for swinging relative to the truck and center spray bar about substantially vertical axes toward and away from the viewer as viewed in FIG. 1.

In FIG. 2, wing spray bar 24, swing joint 34, and an end portion of center spray bar are illustrated in greater detail. Each of the wing spray bars and the center spray bar comprises an elongated hollow box beam closed at both its ends. The hollow interior of each bar provides a passage through which fluid may flow.

An elongated hollow support arm 40 has a lower portion 40a which extends along and is secured to one side of spray bar 24, a central, or riser, portion 4b which projects at an angle upwardly from the end of swing bar 24 nearest center bar 20, and an upper portion 400 which extends above center bar 20. As is best seen in the broken-away portion of FIG. 2, a center, or dividing, plate 42 within arm 40 divides the interior of the arm into a pair of parallel passages 44, 46. Passage 44 is disposed on the side of dividing plate 42 opposite the viewer in FIG. 2, while passage 46 is on the'side of dividing plate 42 nearest the viewer. Passage 44 extends substantially fully to the left end of spray bar 24 in FIG. 2 and opens into spray bar 24 through an inlet opening adjacent its left end. Passage 46 opens into the passage of spray bar 24 through an outlet opening at the right end of the spray bar. Thus, a flow of fluid entering passage 44 at the swing joint may follow the path indicated by the arrows, progressing to the left in passage 44, into the inlet opening at the left end of spray bar 24, through the passage of spray bar 24 to its right, or outlet end, and then into passage 46, and back to the swing joint.

Referring to FIGS. 2 and 3, swing joint 34 includes a hollow base section, or housing, 50 which is mounted in a substantially stationary position relative to the truck and center spray bar 20. The base section is secured to the truck, as through a flange 52 which has an opening extending therethrough communicating directly with a first port 54 in base section 50. Referring specifically to FIG. 2, a second port opening through a side of base section 50 has an end of an elongated conduit 56 connected thereto. The opposite end of conduit 56 is connected to what may be considered the inlet end of the fluid flow passage extending through center spray bar 20. A third port in base section 50, indicated generally at 60 in FIG. 3, has an end of another conduit 64 connected thereto. The opposite end of conduit 64 is connected to the fluid flow passage of center bar 20 adjacent conduit 56.

A fluid-control valve 66 is interposed in conduit 64 between base section 50 and spray bar 20. The valve includes a closure plate 68 mounted for rotation with a pin 70 between the open position shown in FIG. 3, permitting direct fluid flow between section 50 and spray bar 20, and a closed position rotated 90 which closes off the conduit. A fluid-actuated ram 71, illustrated in dot-dashed outline in FIG. 2, is operatively connected through an arm 72 to pin 70 for rotating the valve between its open and closed positions upon extension and retraction of the ram.

Referring again to FIG. 3, an upright, cylindrical support 74 is secured to and projects upwardly from section 50. A conduit 82 is received in support 74 and is supported by a support ring 75 for rotation therein about an upright axis 84 extending centrally of the conduit. A sealing ring 77 interposed between conduit 82 and support 74 provides a fluid-tight seal therebetween.

Referring still to FIG. 3, a substantially fluid-tight compartment 76 is disposed within base section 50. The port through which conduit 56 is connected into the base section opens solely into compartment 76. An elongated upright conduit 80 concentric with conduit 82 is sealingly connected to and opens at its lower end into compartment 76.

An upper housing is sealingly secured to conduit 82 for rotation therewith about axis 84. As is seen in FIG. 3, conduit 82 opens at its upper end into housing 90 and at its lower end into section 50. An upright projection 92 secured to the top of housing 90 is joumaled in the outer end of a brace arm 94 which, as is best seen in FIG. 1, is secured to the rear end of truck 10. Brace arm 94 permits rotation of the housing about axis 84 while maintaining it in an upright position.

A cylindrical support 98 is secured to and projects substantially horizontally outwardly from one side of section 90. A conduit 102 is received in support 98 and is joumaled for rotation therein about a horizontal axis 104. A connecting ring 99 connects conduit 104 to support 98 to prevent axial movement therebetween. A sealing ring 101 interposed between support 99 and conduit 102 provides a fluid-tight seal therebetween.

An end portion of support arm 40 is secured to conduit 102 for rotation therewith about both of axes 84, 104. As is seen in FIG. 3, conduit 102 opens at one of its ends into passage 44 of the support arm and at its other end opens into housing 90.

A second fluid-tight compartment, indicated generally at 96 in FIG. 3, within housing 90 is joumaled on the upper end of conduit 80 for rotation about axis 84. Conduit 80 opens into compartment 96 and the fluidtight seal is provided about their journal connection.

Another elongate conduit 100, concentric with conduit 102, is sealingly connected at one of its ends to and opens into compartment 96. The opposite, or outer, end of conduit opens into passage 46 of support arm 40 and is sealingly connected to divider plate 42 to prevent fluid from flowing therepast between passages 42, 44.

Arm 40 and wing spray bar 24 secured thereto, thus are mounted for rotation about a horizontal axis 104 and about upright axis 84. The portion of base section 50 surrounding compartment 76, the space between conduits 80, 82, the portion of housing 90 surrounding compartment 96, and the space between conduits 100, 102 provide a fluid flow path which extends from port 54in the base section to passage 44 in the support arm, and thus to one end of the passage in spray bar 24. Conduit 100, compartment 96, conduit 80, and compartment 76, in turn, define a discrete fluid flow path extending from passage 46 in support arm 40 to the port which opens into conduit 56. Thus, the swing joint provides a pair of angularly disposed axes about which spray bar 24 may swing while providing discrete fluid flow paths extending therethrough.

Suitable biasing means, such as tension spring 108 which extends between the truck and spray bar 24, and stop means may be provided to yieldably hold a wing spray bar in the position illustrated in FIG. 2, in substantially axial alignment with center bar 20. Such biasing and stop means preferably yieldably bias the wing spray bar to such position and hold it there until such time as an obstruction is engaged by the spray bar, at which time the biasing and stop means permit swinging of the spray bar to ride over or around the obstruction as the truck progresses.

Although only the left wing spray bar 24, its support arm 40, and swing joint 34 have been described in detail herein, it should be understood that the right wing spray bar 26, its associated support arm and swing joint 36 are similarly constructed.

Each spray bar has a plurality of spray devices, indicated generally at in FIGS. 2 and 4, mounted thereon. As best illustrated in FIG. 4 a spray device includes an elongate, cylindrical guide sleeve 112 which extends vertically through and is sealingly secured in the top and bottom walls of the spray bar. The sleeve has at least a pair of relatively large openings 114, 116 formed in its sides through which openings fluid may flow freely as it circulates in the spray bar. A spray head 120 having an orifice 122 extending therethrough is sealingly secured in the bottom of sleeve 112. The upper end of the orifice communicates with the interior of the spray bar and the outer, or lower, end opens to the atmosphere. A seat 126 surrounds the upper end of orifice 122.

A valve stem 132 extends vertically and slidably through the upper end of sleeve 112. Seals (not shown) interposed between the stern and guide provide a fluidtight seal therebetween.

A poppet valve head 130 mounted on the lower end of valve stem 132 is shiftable with the valve stem between a closed position as shown in FIG. 4, sealingly engaging seat 126 to close off the orifice, and an open position raised a distance above the valve seat to permit fluid flow through the orifice.

A nut 136 having a pin 138 secured thereto and projecting outwardly from one of its sides, is screwed onto the threaded upper end of valve stem 132. A sleeve 140 surrounds stem 132 above nut 136 and a lock nut 142 is screwed tight against the top of sleeve 140 to lock it and nut 136 in a desired position on the stem.

Pin 138 is received in a cutout 146 of a connecting block 148. A pair of vertically spaced pins 150, 152 extend across cutout 146 and engage the top and bottom surfaces of pin 138, respectively.

Referring specifically to FIG. 2, a plurality of spaced connecting blocks 148 associated with separate poppet valve stems on a spray bar are secured on a common shaft which is journaled for rotation in a pair of spaced support blocks 162 atop the spray bar. A connecting block in such a group of connecting blocks is connected through a swing bar 166 to the rod end of a ram 170. The connection between the ram and connecting blocks is such that when the ram is contracted, the connecting blocks are lowered as illustrated in FIGS. 2 and 4, holding their associated poppet valves closed against seats 126. Extension of a ram 170 swings its associated connecting blocks upwardly and lifts their associated poppet valve heads away from the orifice seats. This opens the orifices, whereby fluid under pressure in a spray bar may be sprayed outwardly through a set of orifices.

Referring specifically to FIG. 5, the inlet side of a pump 176 is connected to tank 12 through a conduit 178 for drawing fluid from the tank and pumping it under pressure through another conduit 180 to port 54 in base section 50 of swing joint 34. Another conduit 182 connects conduit 180 with a similar port 183 in the base section of swing joint 36. A valve 184 in conduit 182 is operable to control the flow of fluid through conduit 182. A conduit 186 having a pressure regulating valve 190 therein connects part 183 to tank 12.

A conduit 192, similar to previously-described conduit 56 connects the end of the passage in center spray bar 20 opposite the end to which conduit 56 is connected to a port on the base section of swing joint 36. Another conduit 194 and a valve 196, similar to previously-described conduit 64 and valve 66, connect the base section of swing joint 36 with the spray bar 20 adjacent conduit 192. Conduits 64 and 94 and their associated valves 66, 196 are also referred to as valve controlled shunt passages through which fluid may be supplied to center spray bar 20.

Describing operation of the apparatus, and referring specifically to the diagram of FIG. 5, the flow through the apparatus indicated by the arrows in FIG. 5 is that which occurs when fluid is circulated through the system without spraying. Explaining further, to circulate fluid from the tank, through the various spray bars and then return to the tank, valves 66, 184, and 196 are closed. Valve 190 is opened to permit free flow therethrough to tank 12. Operation of pump 176 pumps fluid from tank 12 through conduit 180 into the base section of swing joint 34, through the flow path provided by conduits 82, 102 in the :swing joint, into pas sage 44 of arm 40 (see FIG. 3), and then to the inlet end of the passage in spray bar 24. The fluid moves through the spray bar to its outlet end and then to passage 46 of arm 40. The fluid travels back through the swing joint via the flow path provided by conduits 100, 80, in swing joint and through conduit 56 into the inlet end of spray bar 20. On leaving spray bar 20 the fluid travels through conduit 192 to the base section of swing joint 36. Fluid entering the base section from conduit 192 flows through one of the passages of the swing arm supporting spray bar 26, and then through spray bar 26. On leaving spray bar 26 the fluid passes through the other passage in the support arm, and then back through the swing joint and outwardly through conduit 186 and valve 190 to return to tank 12. Such operation provides substantially constant recirculation of fluid in the system for reheating to inhibit clogging of the material in the passages.

When it is desired to spray fluid, pressure regulating valve 190 is adjusted to a fairly high pressure rating to restrict fluid return to tank 12. Valves 184, 66, and 196 are opened. On operation of pump 176 fluid will flow in substantially equal quantities through conduits 180, 182 to the base sections of both of swing joints 34, 36. As fluid is supplied to the bases of both swing joints it will be supplied in substantially equal quantities and at substantially equal pressures through the support arms of the swing joints to opposed wing spray bars 24, 26. Since valves 66, 196 are now open also, a quantity of fluid will be shunted directly through the base sections of the swing joints to opposite ends of center spray bar 20. Extension of rams 170 on the spray bars opens the spray valves on the underside of the spray bars to spray fluid from the bars onto an underlying surface, such as a roadway. Since fluid is supplied at substantially equal pressures to wing spray bars 24, 26, and center spray bar 20, all of the spray bars will be able to spray substantially equal quantities of fluid onto the underlying surfaces.

It should be apparent from the above description that the apparatus provides novel means for mounting spray bars for swinging about multiple axes allowing them to be swung vertically to compact stored positions alongside the vehicle on which they are mounted for traveling, and also for swinging horizontally to move out of the way of obstructions which they might encounter while working. The swing joints also permit continuous fluid flow therethrough throughout any such swinging movement of the spray bar relative to the vehicle on which it is mounted.

While a specific embodiment of the invention has been described herein, it should be apparent to those skilled in the art that variations and modifications are possible without departing from the spirit of the invention.

It is claimed and desired to secure by Letters Patent:

1. A vehicle-carried spray bar assembly for road surfacing comprising a spray bar with fluid supply and return passages defined therein and having fluid-dispensing means thereon adapted, in operative position, to extend laterally and substantially horizontally to one side of the vehicle, and

a swing joint mounting said bar enabling the bar to swing in one direction which is vertically about a substantially horizontal axis extending longitudinally of the vehicle and in another direction which is about an upright axis, said swing joint including a section mounted substantially stationary relative to said vehicle, a swing section mounted on such stationary section for rotation relative thereto about said vertical and horizontal axes, means mounting said spray bar on said swing section for rotation therewith, and means defining a pair of fluid flow paths extending through said stationary and swing sections communicating with the supply and return passages of the spray bar.

2. The spray bar assembly of claim 1, which further.

comprises another spray bar substantially aligned with said first-mentioned spray bar with the latter in its said operative position, and said return passage defined in said swing joint communicates with an end of said other spray bar.

3. The spray bar assembly of claim 2, which further comprises fluid supply means communicating with the supply passage in the swing joint spray bar and a valvecontrolled shunt passage extending between said fluid supply and said other spray bar operable selectively to accommodate or inhibit fluid flow directly from said supply to said other spray bar.

4. Apparatus for spreading fluid comprising a first spray bar having a fluid flow passage extending therethrough,

a second spray bar having a fluid flow passage extending therethrough,

supply means for supplying fluid under pressure to said bars, and

a swing joint mounting said second bar for swinging relative to said first bar about a pair of axes disposed at substantial angles relative to each other, including a section mounted substantially stationary relative to said first bar, conduit means connecting said supply means and first spray bar to said stationary section, a swing section mounted on said stationary section for rotation relative thereto about said angularly disposed axes, means mounting said second spray bar on said swing section for rotation therewith, and means defining a pair of fluid flow paths extending through said stationary and swing sections with one of said paths providing fluid communication between said supply means and one end of the passage of said second spray bar, and the other path providing fluid communication between the other end of said passage of the second spray bar and one end of the passage in the first spray bar.

5. The apparatus of claim 4, which further comprises another conduit connecting said fluid flow passage of the first spray bar to said stationary section, which other conduit is connected through a flow path in the stationary section directly to said supply means, and a valve in said conduit actuatable selectively to control fluid flow through said other conduit.

6. The apparatus of claim 4, wherein said swing joint comprises a first pair of substantially concentric conduits mounted on said stationary section with their center axis extending along one of said axes of rotation and at least the outer of said conduits being journaled for rotation about said axis.

7. The apparatus of claim 6, wherein said swing joint further comprises another pair of substantially concentric conduits mounted on said first-mentioned conduits for rotation therewith about said one axis and extending outwardly therefrom with their center axis extending along the other of said axes and at least one of the conduits in said second pair being mounted for rotation about said other axis, said second spray bar being mounted on said second pair of conduits for rotation therewith.

8. The apparatus of claim 7, wherein one set of ends of the first pair of conduits are disposed adjacent one set of ends of the second pair of conduits and which further comprises means connecting the adjacent ends of the inner conduits in said pairs to each other whereby they define one of said fluid flow paths and means connecting the adjacent ends of the outer conduits in said pairs to each other whereby they define the other fluid flow path.

9. The apparatus of claim 4, which further comprises an orifice on a spray bar through which fluid may be sprayed from a passage, a valve seat surrounding one end of said orifice, and a poppet valve shiftable between a closed position sealingly engaging said seat and an open position spaced from said seat.

10. Apparatus for spreading fluid comprising a spray bar having a fluid flow passage extending therethrough with spaced inlet and outlet ends, means for supplying fluid under pressure to said spray element, and

mounting means interconnecting the spray bar and supply means permitting swinging of the one relative to the other about a pair of axes disposed at a substantial angle relative to each other, including a first section having an inlet port connected to said supply means and an outlet port, a second section mounted on said first section for rotation about said angularly disposed axes relative thereto, and means defining a pair of fluid flow paths extending through said first and second sections, with one of said paths connecting said inlet port to the inlet end of said fluid flow passage of the spray bar, and the other path connecting said outlet port to the outlet end of said fluid flow passage of the spray bar.

11. Apparatus for spreading fluid comprising a first spray bar having a fluid flow passage extending therethrough,

a second spray bar having a fluid flow passage extending therethrough,

supply means including a fluid holding tank and a pump for supplying fluid under pressure from said tank to said spray bars, and

means interconnecting said supply means and spray bars adjustable selectively between a first condition operable to channel a flow of fluid in series from said supply means through said first spray bar, then through said second spray bar, and then return to said tank, and a second condition operable to channel a flow of fluid to said first and second spray bars concurrently.

12. The apparatus of claim 11, wherein said means interconnecting the supply means and spray bars comprises a swing joint interposed between the supply means, first spray bar, and second spray bar, mounting said first spray bar for swinging relative to said second spray bar, said swing joint including means defining a pair of fluid flow paths extending therethrough, one of which interconnects said pump and one end of said passage of the first spray bar, and the other of which interconnects the other end of the passage of the first spray bar and the passage of the second spray bar.

13. The apparatus of claim 12, which further comprises a conduit connecting the fluid flow passage of 10 said second spray bar directly to said supply means a valve in said conduit selectively adjustable between a closed position preventing fluid flow therethrough with the apparatus in its first condition and an open position permitting fluid flow therethrough with the apparatus in its second condition.

14. The apparatus of claim 12, wherein said flrst spray bar is disposed adjacent one end of the second spray bar, and which further comprises a third spray bar having a fluid flow passage extending therethrough disposed adjacent the opposite end of said second spray bar, a second swing joint interposed between said tank, second bar, and third bar permitting swinging of said third bar relative to said second bar, and means within said second swing joint defining a pair of fluid flow paths, one of which paths provides fluid communication between said passage of the second spray bar and one end of the passage of the third spray bar, and the other of which paths provides fluid communication between the opposite end of the passage of the third bar and the tank.

15. The apparatus of claim 14, which further comprises conduit means connecting the outlet side of said pump to said other fluid flow path of the second swing joint and a valve in said conduit operable selectively to control fluid flow therethrough.

16. The apparatus of claim 15, which further com prises a pressure regulating valve interposed between said tank and the point at which said conduit means from the pump joins with said flow path of the second swing joint. 

1. A vehicle-carried spray bar assembly for road surfacing comprising a spray bar with fluid supply and return passages defined therein and having fluid-dispensing means thereon adapted, in operative position, to extend laterally and substantially horizontally to one side of the vehicle, and a swing joint mounting said bar enabling the bar to swing in one direction which is vertically about a substantially horizontal axis extending longitudinally of the vehicle and in another direction which is about an upright axis, said swing joint including a section mounted substantially stationary relative to said vehicle, a swing section mounted on such stationary section for rotation relative thereto about said vertical and horizontal axes, means mounting said spray bar on said swing section for rotation therewith, and means defining a pair of fluid flow paths extending through said stationary and swing sections communicating with the supply and return passages of the spray bar.
 2. The spray bar assembly of claim 1, which further comprises another spray bar substantially aligned with said first-mentioned spray bar with the latter in its said operative position, and said return passage defined in said swing joint communicates with an end of said other spray bar.
 3. The spray bar assembly of claim 2, which further comprises fluid supply means communicating with the supply passage in the swing joint spray bar and a valve-controlled shunt passage extending between said fluid supply and said other spray bar operable selectively to accommodate or inhibit fluid flow directly from said supply to said other spray bar.
 4. Apparatus for spreading fluid comprising a first spray bar having a fluid flow passage extending therethrough, a second spray bar having a fluid flow passage extending therethrough, supply means for supplying fluid under pressure to said bars, and a swing joint mounting said second bar for swinging relative to said first bar about a pair of axes disposed at substantial angles relative to each other, including a section mounted substantially stationary relative to said first bar, conduit means connecting said supply means and first spray bar to said stationary section, a swing section mounted on said stationary section for rotation relative thereto about said angularly disposed axes, means mounting said second spray bar on said swing section for rotation therewith, and means defining a pair of fluid flow paths extending through said stationary and swing sections with one of said paths providing fluid communication between said supply means and one end of the passage of said second spray bar, and the other path providing fluid communication between the other end of said passage of the second spray bar and one end of the passage in the first spray bar.
 5. The apparatus of claim 4, which further comprises another conduit connecting said fluid flow passage of the first spray bar to said stationary section, which other conduit is connected through a flow path in the stationary section directly to said supply means, and a valve in said conduit actuatable selectively to control fluid flow through said other conduit.
 6. The apparatus of claim 4, wherein said swing joint comprises a first pair of substantially concentric conduits mounted on said stationary section with their center axis extending along one of said axes of rotation and at least the outer of said conduits being journaled for rotation about said axis.
 7. The apparatus of claim 6, wherein said swing joint further comprises another pair of substantially concentric conduits mounted on said first-mentioned conduits for rotation therewith about said one axis and extending outwardly therefrom with their center axis extending along the other of said axes and at least one of the conduits in said second pair being mounted for rotation about said other axis, said second spray bar being mounted on said second pair of conduits for rotation therewith.
 8. The apparatus of claim 7, wherein one set of ends of the first pair of conduits are disposed adjacent one set of ends of the second pair of conduits and which further comprises means connecting the adjacent ends of the inner conduits in said pairs to each other whereby they define one of said fluid flow paths and means connecting the adjacent ends of the outer conduits in said pairs to each other whereby they define the other fluid flow path.
 9. The apparatus of claim 4, which further comprises an orifice on a spray bar through which fluid may be sprayed from a passage, a valve seat surrounding one end of said orifice, and a poppet valve shiftable between a closed position sealingly engaging said seat and an open position spaced from said seat.
 10. Apparatus for spreading fluid comprising a spray bar having a fluid flow passage extending therethrough with spaced inlet and outlet ends, means for supplying Fluid under pressure to said spray element, and mounting means interconnecting the spray bar and supply means permitting swinging of the one relative to the other about a pair of axes disposed at a substantial angle relative to each other, including a first section having an inlet port connected to said supply means and an outlet port, a second section mounted on said first section for rotation about said angularly disposed axes relative thereto, and means defining a pair of fluid flow paths extending through said first and second sections, with one of said paths connecting said inlet port to the inlet end of said fluid flow passage of the spray bar, and the other path connecting said outlet port to the outlet end of said fluid flow passage of the spray bar.
 11. Apparatus for spreading fluid comprising a first spray bar having a fluid flow passage extending therethrough, a second spray bar having a fluid flow passage extending therethrough, supply means including a fluid holding tank and a pump for supplying fluid under pressure from said tank to said spray bars, and means interconnecting said supply means and spray bars adjustable selectively between a first condition operable to channel a flow of fluid in series from said supply means through said first spray bar, then through said second spray bar, and then return to said tank, and a second condition operable to channel a flow of fluid to said first and second spray bars concurrently.
 12. The apparatus of claim 11, wherein said means interconnecting the supply means and spray bars comprises a swing joint interposed between the supply means, first spray bar, and second spray bar, mounting said first spray bar for swinging relative to said second spray bar, said swing joint including means defining a pair of fluid flow paths extending therethrough, one of which interconnects said pump and one end of said passage of the first spray bar, and the other of which interconnects the other end of the passage of the first spray bar and the passage of the second spray bar.
 13. The apparatus of claim 12, which further comprises a conduit connecting the fluid flow passage of said second spray bar directly to said supply means a valve in said conduit selectively adjustable between a closed position preventing fluid flow therethrough with the apparatus in its first condition and an open position permitting fluid flow therethrough with the apparatus in its second condition.
 14. The apparatus of claim 12, wherein said first spray bar is disposed adjacent one end of the second spray bar, and which further comprises a third spray bar having a fluid flow passage extending therethrough disposed adjacent the opposite end of said second spray bar, a second swing joint interposed between said tank, second bar, and third bar permitting swinging of said third bar relative to said second bar, and means within said second swing joint defining a pair of fluid flow paths, one of which paths provides fluid communication between said passage of the second spray bar and one end of the passage of the third spray bar, and the other of which paths provides fluid communication between the opposite end of the passage of the third bar and the tank.
 15. The apparatus of claim 14, which further comprises conduit means connecting the outlet side of said pump to said other fluid flow path of the second swing joint and a valve in said conduit operable selectively to control fluid flow therethrough.
 16. The apparatus of claim 15, which further comprises a pressure regulating valve interposed between said tank and the point at which said conduit means from the pump joins with said flow path of the second swing joint. 